1) Field of the Invention
The invention herein relates to an environmental protection compliant, higher productivity footwear vacuum dryer and conveyance apparatus comprised of a conveyor belt situated in between the two sides of a work platform and on which is disposed a number of footwear placement rod support and footwear placement tray units that convey footwear soles and upper coverings. The conveyor belt moves past one or more heating boxes and vacuum activation boxes and is accessible at the intervals between adjoining heating box and vacuum activation boxes the exact number of which is determined by the type of footwear and the type of adhesive utilized to bind the footwear. The hot air current circulatory channels inside the heating boxes increases heating efficiency and reduces electric power consumption. Inside the vacuum activation boxes, moisture content is evacuated and footwear of different material are warmed by radiated heat, thereby preventing damage to the footwear, while also activating the adhesive applied on the footwear to facilitate adhesion between the soles and upper coverings of the footwear. The adhesive fumes generated by the heating process are drawn into air intake ports along the two sides of the conveyor belt and pass through a conjoined pipeline from the heating device into the intake ports of an air baffling and convergence flow distribution system to recycle the adhesive fumes accumulated in the heating device to minimize adhesive vapor emanations. At the same time, the adhesive fumes inside the heating device and the vacuum drying device are discharged through an exhaust hood installed at the upper end, where the adhesive fumes are filtered out through an activated carbon isolation layer, which not only increases production efficiency, but also minimizes environmental pollution, simplifies the production process, reduces manpower requirements, lowers production costs, and effectively achieves environmental protection capability in an economical and practical way.
2) Description of the Prior Art
Conventional footwear production machines are available in an enormous range of types based on the particular utilization and footwear variety. Taking athletic footwear as an example, the final stage of construction requires the adhesion of the prefabricated shoe sole to the upper covering. Prior to the conjoimnent, an adhesive must be applied to the sole and the prefabricated upper covering at the area of adhesion and then be subjected to a drying process utilizing a footwear drying machine to cure the adhesive. If the adhesive lacks adhesiveness after drying, the drying period must be controlled to obtain an effective degree of adhesivness. While controlling the degree of adhesiveness, excessive or insufficient drying readily occurs that results in adhesion flaws, with the constant inspection of temperature by the operating personnel being very inconvenient. Furthermore, the footwear sole and upper covering may be made of different materials which would require the utilization of different types of adhesives as well as varying drying temperatures and periods. On the production line, the footwear upper coverings and soles are situated on the same assembly line and are conveyed past a footwear drying machine operating at the same temperature. If the sole is fabricated of a differing material, most footwear upper coverings can withstand a higher temperature than footwear soles due to the variance in construction material. Furthermore, there are different types of adhesives available at different costs and production line requirements that can be generally classified into three main types: oil-based, water-based, and hot-melt adhesives. Of these, the lowest cost type is the oil-based adhesive. However, this type requires the longest drying process and involves a greater utilization of drying machines, while the production line configuration must be quite lengthy, occupying considerable space since there must also be adequate access to the conveyor belt moving the footwear soles and upper coverings between each footwear drying machine. Since it is not possible to downscale the process and, furthermore, manpower requirements are proportionately increased, high footwear production costs and greater operating space prerequisites are unavoidable. It is of course possible to lower production costs and downscale the production process by utilizing water-based and hot-melt adhesives in that a lesser number of dry machines are required. While a minimum of two more drying machines has to be employed to output finished products, but the said space and costs still cannot be reduced considerably. Furthermore, a vacuum sulfurizing machine is required for shaping after adhesion, with the procedure necessarily involving the conveyance of the adhered footwear to another mechanical processing section which raises the defect rate and, furthermore, requires a larger number of machines, thereby increasing production costs, and reducing competitiveness. Additionally, the unpleasant fumes produced after the adhesive is heated pollutes the air and adversely affects worker health.